Heat Resilience

In Madison, and across Wisconsin, temperatures are on the rise

"A heat wave will slam Madison over the coming days," the  Wisconsin State Journal  reported in late August of 2023. Over the next few days, sweltering temperatures swept across much of Wisconsin. The heat index, a measure combining temperature and humidity to estimate how hot it feels, soared above 110 degrees. In some areas of Wisconsin, the heat index  topped 120 degrees .

Extreme heat events like the heatwave in August 2023 are expected to triple by 2050 as a result of climate change. Wisconsin will also see hotter nighttime temperatures and warmer winters over the coming decades,  according to the Wisconsin State Climatology Office. 

Explore the map below to see what average July temperatures are like in your neighborhood. Darker colors mean higher temperatures.

Urban heat islands make extreme heat worse 

While climate change is increasing temperatures for everyone, some areas are hotter than others. Cities tend to have higher temperatures than more suburban or rural areas. Structures like buildings, roads, and other infrastructure absorb and re-emit the sun's heat more than natural landscapes like forests and water bodies. As a result, areas where these structures are concentrated become pockets of higher temperature, often called urban heat islands.

The location of urban heat islands are driven by land cover and development patterns. Impervious surfaces (like roads and sidewalks) absorb and retain heat and create hot spots in the city. Cars and factories also contribute to higher heat. Alternatively, trees and plants cool the air by releasing water vapor through their leaves, lowering the temperature in green areas.

Heat waves are dangerous, even deadly

Extreme heat poses immediate and longer-term threats to our health. Heat waves kill more people in the US than any other weather event. In 2023, the Wisconsin Department of Health Services reported  10 deaths and 750 emergency room visits  related to heat. Extreme heat events pose acute, catastrophic risks to public health in places with cooler climates like Wisconsin, because these events have been infrequent in the past.

During a heat wave, watch out for symptoms of heat exhaustion and heat stroke in yourself, friends, and family. Anyone can experience heat exhaustion, even if it's hot for a short time.

Low and moderately intense heat events can cause heat exhaustion for certain groups of people:

• Small children
• People who are 65+ years old
•  People who are pregnant 
  • Exposure to heat is associated with an increased risk of preterm and early term birth, low and decreased birth weight, stillbirth, and harmful newborn stress.
• People with certain medical conditions, including cardiovascular health issues (hypertension and heart disease), mental health problems, respiratory issues (asthma and COPD), and diabetes.
• People who lack access to air conditioning or other cooling technology
• People who are experiencing homelessness
•  People who work outdoors  

High nighttime temperatures add to the danger of heat-related illness, as people may not get a chance to cool down and recover.

In the long term, extreme heat leads to increased summertime peak energy demand and energy costs, disruptions to power and transportation infrastructure, reduced air and water quality, and increase greenhouse gas emissions.

Stay safe during extreme heat events

Public Health Madison & Dane County suggests the following strategies for staying safe during extreme heat events. 

• Stay in air-conditioned buildings. If you need a cool place to stay, public places such as local senior and community centers, libraries, and malls are good options. Call ahead to confirm their hours.

Zoom in to see places in your neighborhood where you can go to cool off.

• Limit outdoor activity, especially midday when it is the hottest part of the day, and avoid direct sunlight.
• Wear loose, lightweight, light-colored clothing.
• Never sit in a parked car or leave a person or pet in a parked car.

• Drink more water than usual and don’t wait until you’re thirsty to drink.
• Drink from two to four cups of water every hour while working or exercising outside.
• Avoid alcohol and liquids containing high amounts of sugar.
• Make sure your family and pets are drinking enough water.

• Check your local news for extreme heat warnings and safety tips.
• Regularly check on friends, loved-ones, and neighbors. Call, text, or drop by.

The  Centers for Disease Control and Prevention (CDC)  provides additional helpful tips, information, and resources to help you stay safe in the extreme heat this summer. 

The City of Madison is collaborating with scientists at the University of Wisconsin at Madison (Professor Chris Kurchark and Elizabeth Berg) to map the impacts of extreme heat. Temperature data was collected across Dane County for nine years, then processed by city staff to create easy to understand maps.